Video MP3 system with apparatus and method for generating and restoring reduced video data

ABSTRACT

A video MP3 system including an audio/video (AV) decoder which further comprises a video decoder for restoring a moving picture signal in a MP3 player for restoring an audio signal, an apparatus and method for generating reduced video data which are appropriate for use in the video MP3 system, and an apparatus and method for restoring the reduced video data are provided. In the apparatus for generating reduced video data operated by a method for generating reduced video data, a video stream compressed according to rules of a MPEG is divided into a motion vector, a discrete cosine transform (DCT) DC coefficient, a DCT AC coefficient, and reduced video data, which are appropriate for use in the video MP3 system, are generated by using the motion vector, the discrete cosine transform (DCT) DC coefficient, and the DCT AC coefficient. In the apparatus for restoring reduced video data operated by a method for restoring reduced video data, an intra-frame is over-sampled by using a discrete cosine transform (DCT) DC coefficient and a DCT AC coefficient, and restored to a picture signal, and an inter-frame is motion compensated by using the motion vector and restored to a picture signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to moving picture experts group (MPEG)video, and more particularly, to a video MP3 system.

2. Description of the Related Art

MP3 is a moving picture experts group (MPEG) layer three and is oneportion of MPEG audio techniques. The MPEG is a study group organizedfor standardizing the compression and multiplexing of moving picturesand sound by an international organization for standardization (ISO) andan international electrotechnical commission (IEC). An MP3 player storesan audio signal, which is reduced according to rules stipulated in MPEGlayer 3, and reproduces the reduced audio signal as a real audio signal.

FIG. 1 is a block diagram of a conventional audio MP3 player. Referringto FIG. 1, the conventional MP3 player includes a data interfacing unit10, a micro-computer 11, a key inputting unit 12, a memory device 13, adisplay 14, an audio decoder 15, an audio reproducer 16, and a speaker17.

The data interfacing unit 10 receives compressed data DATA of an audiosignal from an MP3 encoder (not shown). The micro-computer 11 controlsthe data interfacing unit 10, receives the compressed data DATA from thedata interfacing unit 10, stores the compressed data DATA in the memorydevice 13, transmits the compressed data DATA stored in the memorydevice 13 to the audio decoder 15, and operates the display 14 accordingto signals received from the key inputting unit 12.

The key inputting unit 12 sends a command requested by a user to themicro-computer 11. The compressed data DATA is stored in the memorydevice 13 under the control of the micro-computer 11, and the display 14performs a display command of the micro-computer 11. The audio decoder15 receives the compressed data DATA and a command from themicro-computer 11 and decodes the compressed data DATA in response tothe command of the micro-computer 11, the audio reproducer 16 receives adecoded signal from the audio decoder 15 to reproduce the decoded signalas an audio signal, and the reproduced signal is output through thespeaker 17.

In the conventional audio MP3 player of FIG. 1, an audio signalcompressed according to the rules of MP3 can be processed, but a videosignal cannot be processed. This is the reason a video file must becompressed in accordance with an international standard such as MPEGvideo compression, and a moving picture can be reproduced only if thecompressed data are decoded by using an exclusive decoder such as anMPEG video decoder.

Thus, in order to process the video signal, an exclusive video decoderand a medium for storing a video signal which is bigger than the audiosignal are required. In the conventional portable audio MP3 player, thecapacity of usable power supply is restrictive. Thus, in order toprocess the video signal, considerable modification of the conventionalportable audio MP3 player is required.

SUMMARY OF THE INVENTION

To solve the above problem, it is a first object of the presentinvention to provide a video MP3 system including an audio/video (AV)decoder which comprises a video decoder capable of implementing a movingpicture.

It is a second object of the present invention to provide an apparatusfor generating reduced video data which are appropriate for use in thevideo MP3 system.

It is a third object of the present invention to provide an apparatusfor restoring reduced video data.

It is a fourth object of the present invention to provide a method forgenerating reduced video data which is appropriate for use in the videoMP3 system.

It is a fifth object of the present invention to provide a method forrestoring reduced video data.

According to a first aspect of the present invention, there is provideda video MP3 system. The video MP3 system includes a data interfacingunit, a memory device, a micro-computer, an audio/video (AV) decoder, anaudio reproducer, and a video reproducer. The data interfacing unitreceives compressed data of an audio signal and reduced data of a videosignal. The memory device inputs and outputs the compressed data of anaudio signal and the reduced data of a video signal. The audio/video(AV) decoder receives the compressed data of the audio signal and thereduced data of the video signal from the micro-computer, decodes thereceived compressed data of the audio signal to output restored audiodata, and decodes the received reduced data of the video signal tooutput restored video data. The micro-computer receives the compresseddata of the audio signal and the reduced data of the video signal fromthe data interfacing unit, stores the compressed data and the reduceddata in the memory device and outputs the compressed data and/or thereduced data stored in the memory device. The audio reproducer receivesthe restored audio data to reproduce the restored audio data as an audiosignal. The video reproducer receives the restored video data toreproduce the restored video data as a video signal.

In one embodiment, the audio/video decoder includes an audio decoder fordecoding the compressed data of the audio signal to output the restoredaudio data and a video decoder for decoding the reduced data of thevideo signal to output the restored video data.

The video decoder can include a de-multiplexer for receiving the reduceddata of the video signal. An over-sampler receives a discrete cosinetransform (DCT) DC coefficient and a DCT AC coefficient from thede-multiplexer to over-sample an intra-frame. A motion compensatorreceives fed back restored video data and a motion vector of the reduceddata of the video signal from the de-multiplexer, motion compensates aninter-frame using the motion vector and outputs the motion compensatedinter-frame. An adder logically adds an output signal of theover-sampler and an output signal of the motion compensator to outputthe restored video data.

In accordance with another aspect of the invention, there is provided anapparatus for generating reduced video data. The apparatus includes avariable length code decoder (VLD), an inverse quantizer (IQ), and amultiplexer. The VLD receives a moving picture experts group (MPEG)video stream and decodes motion displacements and discrete cosinetransform (DCT) data of the received MPEG video stream to output amotion vector, a quantization scale, and a quantization coefficient. TheIQ receives the quantization scale and the quantization coefficient andperforms inverse quantization of the received quantization scale andquantization coefficient to output a DCT DC coefficient and a DCT ACcoefficient. The multiplexer multiplexes the motion vector, the DCT DCcoefficient, and the DCT AC coefficient to generate reduced video data.

In accordance with another aspect of the invention, there is provided anapparatus for restoring reduced video data. The apparatus includes ade-multiplexer, an over-sampler, a motion compensator, and an adder. Thede-multiplexer receives reduced video data. The over-sampler receives adiscrete cosine transform (DCT) DC coefficient and a DCT AC coefficientof the reduced video data from the de-multiplexer to over-sample anintra-frame. The motion compensator receives predetermined, fed backrestored video data and a motion vector of the reduced video data fromthe de-multiplexer, motion compensates an inter-frame using the motionvector and outputs the motion compensated inter-frame. The adderlogically adds an output signal of the over-sampler and an output signalof the motion compensator to output the restored video data.

In accordance with another aspect of the invention, there is provided amethod for generating reduced video data. According to the method, anMPEG video stream is received, and motion displacements and discretecosine transform (DCT) data of the received MPEG video stream aredecoded to generate a motion vector, a quantization scale, and aquantization coefficient. The quantization scale and the quantizationcoefficient are received, and inverse quantization of the receivedquantization scale and quantization coefficient are performed, togenerate a DCT DC coefficient and a DCT AC coefficient. The motionvector, the DCT DC coefficient, and the DCT AC coefficient aremultiplexed to generate reduced video data.

In accordance with another aspect of the invention, there is provided amethod for restoring reduced video data. In accordance with the method,reduced video data is received, and the received reduced video data isdivided into a motion vector, a discrete cosine transform (DCT) DCcoefficient, and a DCT AC coefficient. An intra-frame is over-sampledusing the DCT DC coefficient and the DCT AC coefficient. An inter-frameis motion compensated using predetermined, fed back restored video dataand the motion vector. An OR operation is performed on data havingundergone the steps of over-sampling and motion compensation to generatethe restored video data.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of theinvention will be apparent from the more particular description of apreferred embodiment of the invention, as illustrated in theaccompanying drawings in which like reference characters refer to thesame parts throughout the different views. The drawings are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

FIG. 1 is a block diagram illustrating an example of a conventionalaudio MP3 player.

FIG. 2 is a block diagram illustrating an embodiment of a video MP3system according to the present invention.

FIG. 3 is a block diagram of an apparatus for generating reduced videodata according to the present invention.

FIG. 4 is a circuit diagram of an apparatus for restoring reduced videodata according to the present invention.

FIG. 5 illustrates a method for counting a DC value of an inter-frameusing a DC value and a motion vector (MV) of a reference frame.

FIG. 6 illustrates a DC coefficient and two AC coefficients amongdiscrete cosine transform (DCT) coefficients.

FIG. 7 illustrates an over-sampling method using the DCT DC coefficientand the two AC coefficients of FIG. 6.

FIG. 8 is a flowchart illustrating the steps of generating reduced videodata in the apparatus for generating reduced video data according to thepresent invention.

FIG. 9 is a flowchart illustrating the steps of restoring reduced videodata in the apparatus for restoring reduced video data according to thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 is a block diagram illustrating an embodiment of a video MP3system according to the present invention. Referring to FIG. 2, thevideo MP3 system includes a data interfacing unit 20, a micro-computer21, a key inputting unit 22, an audio/video (AV) decoder 24, an audioreproducer 25, a speaker 26, a video reproducer 27, and a monitor 28.

The data interfacing unit 20 receives compressed data of an audio signalor reduced data of a video signal in response to a command of themicro-computer 21. The micro-computer 21 adjusts the data interfacingunit 20, receives data from the data interfacing unit 20 and stores thedata in the memory device 23. The micro-computer 21 operates the monitor28 in response to the signal of the key inputting unit 22, and transmitsthe compressed data stored in the memory device 23 to the AV decoder 24.

The key inputting unit 22 allows the micro-computer 21 to input acommand so that a user can perform a desired function, and the memorydevice 23 inputs/outputs the data through the micro-computer 21. The AVdecoder 24 includes an audio decoder 24-1 and a video decoder 24-2. TheAV decoder 24 decodes the compressed data of the audio signal inresponse to the command of the micro-computer 21 in the audio decoder24-1, transmits the compressed data to the audio reproducer 25, decodesthe reduced data of the video signal in the video decoder 24-2 andtransmits the reduced data to the video reproducer 27.

The operation of the video MP3 system according to signal flow of thecompressed data will be described with reference to FIG. 2. Thecompressed data of the audio signal or the reduced data of the videosignal, which are applied to the data interfacing unit 20 of the videoMP3 system, are stored in the memory device 23 in response to thecommand of the micro-computer 21 and transmitted to the AV decoder 24 inresponse to another command of the micro-computer 21. The compresseddata of the audio signal are decoded in the audio decoder 24-1,reproduced to an audio signal in the audio reproducer 25, and outputthrough the speaker 26. The reduced data of the video signal are decodedin the video decoder 24-2, reproduced to a video signal in the videoreproducer 27, and output through the monitor 28.

As described above, in the video MP3 system according to the presentinvention, the compressed data of the audio signal can be reproduced byusing the audio decoder, and the reduced data of the video signal can bereproduced by using the video decoder.

Moving picture data used for display on a conventional PC monitor mustbe reduced to moving picture data which are appropriate for the size ofa liquid crystal display (LCD) panel of a mobile phone similar to thesize of a portable MP3 system according to the present invention.

FIG. 3 is a block diagram of an apparatus for generating reduced videodata according to the present invention. Referring to FIG. 3, theapparatus for generating reduced video data includes a variable lengthdecoder (VLD) 31, an inverse quantizer (IQ) 32, and a multiplexer 33.

The VLD 31 receives a moving picture experts group (MPEG) video streamand decodes motion displacements and discrete cosine transform (DCT)data. The IQ 32 receives a quantization scale (Q scale) and aquantization coefficient (QC) from the VLD 31, performs de-quantization,and outputs a DCT DC coefficient and a DCT AC coefficient. Themultiplexer 33 receives a motion vector (MV) from the VLD 31 and the DCTDC coefficient and the DCT AC low frequency (LF) coefficient from the IQ32, multiplexes the motion vector (MV), the DCT DC coefficient and theDCT AC low frequency (LF) coefficient, and outputs the reduced data(reduced video stream) of the video signal.

Referring back to FIG. 3, a method for generating reduced data of thevideo signal is to sort and multiplex the DCT low frequency coefficientand the motion vector of the MPEG video stream. In the MPEG fordiscrete-cosine-transforming one 8×8 (64)-pixel block and compressingdata, the DCT DC coefficient denotes an average value for the 8×8(64)-pixel block. In the case of using the DCT DC coefficient, one framecan be represented with 1/64 of the picture data to be indicated,thereby obtaining a down-sampling effect.

An over-sampling process must be performed to restore the size of apicture which is encoded to a MPEG. However, one or two low frequency(LF) coefficients (AC coefficients) among DCT coefficients is or areincluded in the reduced video picture. Also, in the MPEG, inter-framesare arranged between intra-frames which are references, therebyincreasing compression efficiency using similarity between frames.

There are 15 frames in one group of pixels (GOP). Among them, a firstframe is an intra-frame, and 14 inter-frames follow. In the case of theintra-frame, all the pixels included in the frame are decoded. However,in the case of the inter-frames, which are composed of a prediction (P)frame and a bi-direction (B) frame, only pixels which are varied withrespect to similarity between intra-frame and the P frame and the Bframe, are decoded.

One GOP I1 through B10 is as follows.

I1 B1 B2 P1 B3 B4 P2 B5 B6 P3 B7 B8 P4 B9 B10 I2

Here, the first frame I1 is an intra-frame, and 14 frames from B1through B10 and P1 through P4 are inter-frames. The last frame 12 of thecolumn is a starting point of a new GOP.

All pixels belonging to the intra-frame I1 are decoded. Among theinter-frames, pixels belonging to a fourth frame P1, a seventh frame P2,a tenth frame P3, and a thirteenth frame P4 are also decoded.

However, the second frame BI is decoded on the basis of picturevariation between the intra-frame I1 and the fourth frame P1. The thirdframe B2 is decoded on the basis of picture variation between the secondframe B1 and the fourth frame P1. Similarly, the fifth frame B3 isdecoded on the basis of picture variation between the fourth frame P1and the seventh frame P2. Hereinafter, the remaining inter-frames aredecoded by the following method.

In the case of an inter-frame among the inter-frames B1 through B10,variation of the inter-frame is very small in comparison with that ofthe front and rear frames. If the small amount of variation is indicatedby using a motion vector and a motion vector is used to indicate data ofeach frame, the amount of data to be indicated for each frame can bereduced. The motion vector denotes the degree of motion with respect toan arbitrary reference frame and by obtaining an average motion vectorfor each block.

Thus, in order to generate the reduced video data which are appropriatefor use in the video decoder according to the present invention, first,the intra-frame is composed of DC coefficients of a reference frame.Next, a DC value of the inter-frame is obtained by using the motionvector.

FIG. 4 is a circuit diagram of an apparatus for restoring reduced videodata according to the present invention. Referring to FIG. 4, theapparatus for restoring reduced video data includes a de-multiplexer(DeMUX) 41, an over-sampler 42, a motion compensator (MC) 43, and anadder 44.

The DeMUX 41 receives a reduced video data and transmits a motion vector(MV) to the MC 43 and a DCT DC coefficient and a low frequency (LF) DCTAC coefficient to the over-sampler 42. The over-sampler 42 over-samplesthe DCT DC coefficient and AC coefficient, which are received from thede-multiplexer 41. The MC 43 receives the motion vector (MV), which isreceived from the DeMUX 41, and an output signal of the adder 44, andoutputs a motion compensation signal to the adder 44. The adder 44performs an AND operation of an output signal of the over-sampler 42 andthe motion compensation signal output from MC 43.

The video data, which are reduced to an appropriate size by using thesame method as that of FIG. 3, are input to the apparatus for restoringreduced video data of FIG. 4 and output as restored video data.

The apparatus for restoring reduced video data divides the receivedreduced video data into the motion vector (MV), the DCT DC coefficient,and the AC coefficient for each frame. That is, the intra-frame I1 isover-sampled by using the DCT DC coefficient and the AC coefficient andis restored to a video picture, and the inter-frames P1 through P4 andB1 through B10 pass through with a motion compensation process by usingthe motion vector (MV) and are restored to a video picture.

FIG. 5 illustrates a method for counting a DC value of an inter-frameusing a DC value and a motion vector (MV) of a reference frame.Referring to FIG. 5, a DC value (DC(P_(ref))) for the present frame isobtained by Equation 1 based on the motion vector for a DC value of areference frame (P_(ref)).DC(P _(ref))=[(P ₁ ×w ₁ ×h ₁)+(P ₂ ×w ₂ ×h ₂)+(P ₃ ×w ₃ ×h ₃)+(P ₄ ×w ₄×h ₄)]w ₁ =w ₃=(8−x), h ₁ =h ₂=(8−y), w ₂ =w ₄ =x, h ₃ =h ₄=y  [Equation 1]

Here, x and y denote motion vectors for the present frame, and P₁through P₄ denote DC values of the reference frame indicated by themotion vectors.

If the reduced data are generated by using the DC value of theintra-frame and the motion vector of the inter-frame by the abovemethod, the reduced data which is smaller than a data stream compressedaccording to the conventional MPEG can be generated so that it isconsiderably more advantageous to use the reduced data in a mobile phoneusing a small capacity memory.

FIG. 6 illustrates a DC coefficient and two AC coefficients amongdiscrete cosine transform (DCT) coefficients. Referring to FIG. 6, theDCT DC coefficient is P, and the two AC coefficients are A1 and A2.

FIG. 7 illustrates an over-sampling method using the DCT DC coefficientand the two AC coefficients of FIG. 6. In FIGS. 7, A, B, C, and D can beindicated by Equation 2.A=PB=Pq Ps αC=Pq Ps β  [Equation 2]

$D = {\frac{\left( {B + C} \right)}{2}\mspace{20mu}{or}\mspace{20mu}\frac{A + B + C}{3}}$

Referring to FIGS. 6 and 7, a picture is enlarged by two or four timesby low frequency (LF) AC coefficients for over-sampling by adding orsubtracting the AC coefficients for the DC coefficients to or from theDC coefficients according to directions.

For example, a vertical over-sampling value B is obtained by adding orsubtracting a varied amount, that is, P×α(0≦α≦1), according to A1 of theDC value for the DC value P. Likewise, a horizontal over-sampling valueC is obtained by adding or subtracting a varied amount, that is,P×β(0≧β≧1), according to A2 of the DC value for the DC value P. In orderto over-sample by four times, the DC value has an average value betweenthe vertical over-sampling value Band the horizontal over-sampling valueC, or an average value of the vertical over-sampling value B, thehorizontal over-sampling value C, and the DC value A.

FIG. 8 is a flowchart illustrating the steps of generating reduced videodata in the apparatus for generating reduced video data according to thepresent invention. Referring to FIG. 8, an MPEG video stream is receivedand motion displacements and DCT data are decoded, thereby generating aquantization scale and a quantization coefficient (step 810). Thequantization scale and the quantization coefficient, which are generatedin step 810, are received, thereby performing inverse quantization andgenerating the DCT DC coefficient and the DCT AC coefficient (step 820).The motion vector in step 810 and the DCT DC coefficient and the DCT ACcoefficient in step 820 are multiplexed (step 830).

FIG. 9 is a flowchart illustrating the steps of restoring reduced videodata in the apparatus for restoring reduced video data according to thepresent invention. Referring to FIG. 9, reduced data are received (step910). The reduced data received in a first step (step 910) are dividedinto a motion vector (MV), a DCT DC coefficient, and a DCT ACcoefficient (step 920). An intra-frame is over-sampled by using the DCTDC coefficient and the DCT AC coefficient divided in step 920 (step930). The data over-sampled in step 930 are restored to a video picture,and returning to step 910, decoding is continuously performed (step950). An inter-frame is motion compensated by using the motion vector(MV) divided in step 920 (step 940). The data compensated in step 940are restored to the video picture, and returning to step 910, decodingis continuously performed (step 960). If the reduced data are no longerapplied, the above operation is completed (step 970).

As described above, a video MP3 system, an apparatus and method forgenerating reduced video data which are appropriate for use in the videoMP3 system, and an apparatus and method for restoring the reduced videodata according to the present invention can use a moving picturesimultaneously as well as an audio signal.

While this invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention as defined by the appended claims.

1. An apparatus for generating display-compatible video data, theapparatus comprising: a variable length code decoder (VLD) for receivinga moving picture experts group (MPEG) video stream and decoding motiondisplacements and discrete cosine transform (DCT) data of the receivedMPEG video stream to output a motion vector, a quantization scale, and aquantization coefficient; an inverse quantizer (IQ) for receiving thequantization scale and the quantization coefficient and performinginverse quantization of the received quantization scale and quantizationcoefficient to output DCT coefficients; and a multiplexer formultiplexing the motion vector, and the DCT coefficients, to generatedisplay-compatible video data.
 2. A method for generatingdisplay-compatible video data, the method comprising: receiving an MPEGvideo stream, decoding motion displacements and discrete cosinetransform (DCT) data of the received MPEG video stream to generate amotion vector, a quantization scale, and a quantization coefficient;receiving the quantization scale and the quantization coefficient andperforming inverse quantization of the received quantization scale andquantization coefficient to generate DCT coefficients; and multiplexingthe motion vector and the DCT coefficients to generatedisplay-compatible video data.
 3. A video MP3 system comprising: aportable enclosure, the contents of which comprise: a micro-computercapable of controlling data processing steps and other components; amemory device coupled to and controlled by the micro-computer, thememory device comprising stored compressed audio data anddisplay-compatible video data; an audio/video (AV) decoder coupled toand controlled by the micro- computer; an audio reproducer coupled tothe audio/video decoder; and a video reproducer coupled to theaudio/video decoder, wherein the AV decoder divides thedisplay-compatible video data into a motion vector, a discrete cosinetransform (DCT) DC coefficient, and a DCT AC coefficient, and generatesrestored video data based on the motion vector the DCT DC coefficientand the DCT AC coefficient.
 4. The system as claimed in claim 3, furthercomprising a data interfacing unit coupled to and controlled by themicro-computer, the data interfacing unit comprising a connector forcommunicating audio and video data to or from an external source.
 5. Thesystem as claimed in claim 3, further comprising a key inputting unitcoupled to the micro-computer.
 6. The system as claimed in claim 5,further comprising a display unit coupled to the video reproducer andthe micro-computer.
 7. The system as claimed in claim 6, wherein themicro-computer processes key inputting unit signals into correspondingcontrol display unit signals and sends the control display unit signalsto the display unit.
 8. The system as claimed in claim 7, wherein themicro-computer also sends control signals to the audio/video (AV)decoder to process display-compatible video data.
 9. The system asclaimed in claim 7, wherein the display unit is sized for a mobilephone.
 10. The system as claimed in claim 3, wherein the audio/video(AV) decoder comprises: an audio decoder; and a video decoder, the videodecoder comprising a de-multiplexer, an over- sampler coupled to thede-multiplexer, a motion compensator coupled to the de- multiplexer, andan adder coupled to the over-sampler and the motion compensator.
 11. Amethod for presenting audio and visual data in a portable device, themethod comprising: storing compressed audio data and display-compatiblevideo data in a memory device of the portable device; transmitting thestored audio data and video data to an audio/video decoder in theportable device; decoding the audio data to an audio signal; anddecoding the display-compatible video data to a video signal compatiblewith a display unit of the portable device, wherein decoding thedisplay-compatible video data to a video signal comprises dividing thedisplay-compatible video data into a motion vector, a discrete cosinetransform (DCT) DC coefficient, and a DCT AC coefficient, and generatingrestored video data based on the motion vector, the DCT DC coefficientand the DCT AC coefficient.
 12. The method as claimed in claim 11,wherein the step of decoding the video data comprises: receiving thestored video data from the memory device; dividing the video data intodiscrete cosine transform (DCT) coefficients and a motion vector;over-sampling an intra-frame using the DCT coefficients to provide anover- sampled signal; motion compensating an inter-frame using themotion vector and a feedback loop of a final video signal to provide amotion compensated signal; and adding the over-sampled signal and themotion compensated signal to generate the final video signal.
 13. Theapparatus as claimed in claim 1, wherein the display- compatible videodata is compatible for display on a portable device.
 14. The apparatusas claimed in claim 13 wherein the portable device is an MP3 device. 15.The method as claimed in claim 2, wherein the display-compatible videodata is compatible for display on a portable device.
 16. The method asclaimed in claim 15, wherein the portable device is an MP3 device.